Yes, WAC505, WAC510 and WAC540 Wireless Access Points are compliant with 802.11ac explicit beamforming requirements.
For more information about explicit beamforming, see What is explicit beamforming and how does it work?
For more information about the IEEE 802.11ac standard, see What is 802.11ac and what are the key differences between 802.11ac Wave 1 and Wave 2?